Place cooked beans in a small bowl. Stir red onion, cilantro, vinegar, soy
sauce, hot oil, and sesame oil into beans. Marinate 20 to 30 minutes at
room temperature.
Bring 2 quarts of water to a boil. Trim dried, tough ends from asparagus
stalks. Slice asparagus on the diagonal. Blanch in boiling water for 3
minutes. Remove from water, drain, and toss with marinated beans.
To serve, place each lettuce leaf on a chilled salad plate. Divide salad
evenly among lettuce leaves. Serves 4.